Pyrithione salts, such as zinc and sodium pyrithione which are commercially available under Olin Corporation's registered trademark Omadine.RTM., are known to have broad antibacterial and antifungal activity. Pyrithione salts have been disclosed for use in personal care items, as illustrated by the disclosures of U.S. Pat. No. 5,015,632 describing the use of chitosan pyrithione as an antimicrobial agent in such products.
Basic lipopeptides, such as polymyxin B, colistin (also called polymyxin E), and octapeptin are known in the art. The primary use of these antibiotics is to treat superficial infections, as disclosed, for example, in U.S. Pat. No. 5,120,711. More specifically, the '711 patent discloses the use of antibiotics, such as polymyxin B, in combination with clotrimazole or chlorquinaldol in the preparation of synergistically active veterinary compositions useful for the treatment of mastitis and metritis. Unfortunately, these lipopeptides are much more expensive than might be desired for use in personal care products. Accordingly, new antimicrobial compositions that are efficaceous yet not prohibitively expensive would be highly desired by the personal care products manufacturing community.